Panel with fire barrier

Abstract

A panel with fire barrier comprises: a metal facing; an insulating foam layer; and at least one fire barrier layer between the metal facing and the foam layer, the fire barrier layer(s) comprising at least one of porous silica; hollow glass microspheres; glass fibres; an inorganic ceramifying composition; a dispersion in a polyurethane polymer matrix or polyurethane/polyisocyanurate polymer matrix or polyurethane/polyurea polymer matrix of expandable graphite. A panel arrangement with fire barrier material in the joint regions between panels, methods of forming the panel and panel arrangement, fire barrier compositions, and reactants for forming the fire barrier compositions are also described.

1 - 13 . (canceled) 
     
     
         14 . A panel comprising:
 a metal facing;   an insulating foam layer; and   at least one fire barrier layer between the metal facing and the insulating foam layer, the fire barrier layer(s) comprising a dispersion of expandable graphite in a polyurethane/polyisocyanurate polymer matrix having isocyanate index 1.8 or more.   
     
     
         15 . A panel as claimed in  claim 14 , wherein the fire barrier layer is continuous and is continuously bonded to the metal facing and to the insulating foam layer. 
     
     
         16 . A panel as claimed in  claim 14 , wherein the fire barrier layer is 2 to 20 mm in thickness. 
     
     
         17 . A method of forming a panel as claimed in  claim 14 , comprising the steps of:
 providing the metal facing with the at least one fire barrier layer;   applying the insulating foam layer in the form of a liquid reaction mixture to the fire barrier layer(s); and   applying a second metal facing to the insulating foam layer.   
     
     
         18 . A method as claimed in  claim 17 , wherein the at least one fire barrier layer (a) is applied in the form of another liquid reaction mixture, or (b) is applied in solid form. 
     
     
         19 . A method as claimed in  claim 18 , wherein the other liquid reaction mixture is used to form the fire barrier layer and comprises a dispersion in an isocyanate-based reaction mixture of expandable graphite.